Self-adjusting plunger.



PATENTED SEPT. 15

G. F. MARSH.

SELF ADJUSTING PLUNGER.

APPLICATION FILED MAY 4, 1903.

N0 MODEL.

m w i My UNITED STATES Patented September 15, 1903.

CHARLES F. MARSH, OF ELGIN, ILLINOIS.

SELF-ADJUSTING PLUNGER.

SPECIFICATION forming part of Letters Patent N0. 738,826, dated September 15, 1903. Application filed May 4,1903. Serial No. 155,637. (No model.)

.To all whom it may concern: v

Be it known that I, CHARLES F. MARSH, a citizen of the United States, residing at Elgin, in the county of Kane and State of Illinois, have invented certain new and useful Improvements in Self-Adjusting Plungers, of which the following is a specification.

In the manufacture of watches or in repairing the same considerable difficulty is experienced in obtaining a firm resting-place for the arbor or center staif of the watch when it is desired to place the hour and minute hands in position on said stafi. By reason of not having a firm foundation upon which this arbor or center staff may rest injury quite frequently results to the jewel-bearings, to the plates, or to the arbor or center staff. When the arbor or center staff is placed in position in the Watch, it has considerable end shake, thus makingit quite difficult to obtain a firm foundation for said staff when placing the hour and minute hands or the other attachments in position on said center staff. Any amount of pressure brought to bear upon the upper end of the center staff has a tendency to cause said staff to bear directly upon the jewel-bearing, which is liable to cause displacement of the jewel or breaking the same, and thus materially injure the watch.

The objects of this invention are to overcome the above objections, and with that end in View I have provided a movement-block carrying an adjustable plunger which is so constructed that when the under surface of the center staff rests upon the point of the plunger the plunger will be depressed to a point which will give the center staff a firm foundation and at the same time take up all end shake of said staff. In this position the plunger can be securely locked by manipulating the locking-lever, and by reason of the center staff resting directly upon the point of the plunger all liability of injuring the jewelbearing will be obviated.

In the accompanying drawings, Figure l is an enlarged sectional View of my improved self-adjusting plunger, partly in elevation, showing the watch and ring in position on the block. Fig. 2 is a plan view of the block and plunger. Fig. 3 is a perspective view of the ring; and Fig. 4 is an enlarged sectional view of the plunger, showing it partly depressed.

. 1 indicates a metal block which is provided with a series of steps 2, gradually diminishing in diameter. The purpose of these steps is to enable the different-sized watch-movements to be secured in the movement-ring and inept-block.

3 indicates a horizontal opening entering the side of the block 1 immediately below the steps 2 and extending to the cen terof block 1.

4 indicates a vertical opening extending through the center of the block 1. This opening is provided near the lower end thereof with the shoulder or spring-support 5.

6 indicates a plunger which is provided near its upper end With the shoulder 7. The upper end of the plunger is cone-shaped and the apex thereof provided with the depression 8.

9 indicates a spiral spring encircling the plunger 6. The upper end of the spiral spring 9 rests against the shoulder 7 and the lower end thereof upon the shoulder 5. This spring is adapted to keep the plunger normally in the upper position.

10 indicates a tapering slot in the lower portion of the plunger 6. This slot tapers slightly toward the top.

11 indicates the locking-pin, one end of which is provided with screw-threads 12,

which engage the screw-threads 13 in the horizontal opening 3. The opposite end of the locking-pin 11 is adapted to engage the slot 10 in the block 1.

14 indicates the handle secured by the locking-pin 11.

an indicates a Watch-movement placed in the movement-ring 16. This ring carries the watch-movement m and is adapted to engage the steps 2 in the movement-block 1.

15 indicates the arbor or center stafi of the watch and is shown in Fig. 1 as restingin the depression 8 of the cone-shaped apex of the plunger 6. l

x and indicate the hour and minute hands.

the same placed in position on the move- The operation is as follows: The watchmo'vement is placed in the movement-ring and the movement-ring placed in position on the movement-block. The plunger being normally held in its upward position will be slightly depressed when the movement is placed in position on the block by reason of the arbor or center staff coming in contact with the apex of the plunger. When the locking-lever is pressed downward, the end of said lever will bear firmly against the wall of the slot in the plunger by reason of the slot tapering where it comes in contact with the end of the locking-lever, thus firmly holding the plunger in position when the lockinglever is secured.

Slight changes can of course be made in the construction and in the arrangements of the several parts herein described without deof this in- Witnesses:

Tnos. J. J UZEK, A. H. RUEGNITZ. 

